package javademo;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.*;
import java.util.concurrent.locks.ReentrantLock;
import java.lang.Thread;
public class Demo {
    public static void main(String[] args) {
        Animal a = new Dog();
        a.method1();
        Set<Object> map = new HashSet<>();
        Object next = map.iterator().next();
        LinkedList<Integer> list = new LinkedList<>();
        ArrayList<Integer> list1 = new ArrayList<>();


    }
}
